The present invention relates to a replaceable top tube which has two engaging ends for respectively hooking to the seat post and the handlebar stem. Each of the engaging ends has a sleeve which is slid along the longitudinal tube of the replaceable top tube.
Bicycles can be carried on outside of cars by using a bicycle carrier which has a clamp device to hold the top tube of the bicycle and two engaging devices are used to fix the bicycle. However, some bicycles have no top tube so that these bicycles cannot be carried on the bicycle carrier. In order to improve the shortcoming, a replaceable top tube is developed and shown in FIGS. 6 to 8. The replaceable top tube 70 includes a tube 71 with two hooks 73 connected to two ends of the tube 71, and two engaging members 70 are pivotally connected to the tube 71. Each of the engaging members 70 has a groove 723 defined in an inside thereof and a hole 722 is defined through the engaging member 70 and communicates with the groove 723. A protrusion 711 extends from the tube 71 so that when the engaging member 70 is pivoted toward the hook 73, the protrusion 711 is slid in the groove 723 and engaged with the hole 722. An inclined surface 721 on the engaging member 70 is matched with another inclined surface 731 defined in a distal end of the hook 73. The two hooks 73 may hook the seat post 60 or the seat tube and the handlebar stem of the bicycle.
The way that the engaging member 70 is pivoted relative to the tube 71 could be interfered by objects on the bicycle so that the user often takes a lot of time to adjust the position of the hooks 73 to successfully hook the seat post 60 and the handlebar stem. Besides, the area of the engaging members 70 is so small that it results a large pressure to the user""s hand.
In accordance with one aspect of the present invention, there is provided a replaceable top tube which comprises an outer tube having a first aperture in a first end thereof and an inner tube has a first end thereof retractably received in a second end of the outer tube. A first sleeve is slidably mounted to the first end of the outer tube and has a first hole which is located in communication with the first aperture. A locking plate is fixedly connected to the first sleeve and a first hook is fixedly connected to the first end of the outer tube. The locking plate is engaged with the first hook when the first sleeve is not pulled. A resilient member is located in the first end of the outer tube and a pushing end extends through the first aperture and the first hole.
A second aperture is defined through a wall of a second end of the inner tube and a second sleeve is slidably mounted to the second end of the inner tube and has a second hole which is located in communication with the second aperture. Another locking plate is fixedly connected to the second sleeve and another hook is fixedly connected to the second end of the inner tube. The another locking plate is engaged with the another first hook when the second sleeve is not pulled.
The primary object of the present invention is to provide a replaceable top tube that has two sleeves which are pulled along the tube so that it is easy to use.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.